Ecological watering requirements in northern Australia, Riversymposium Conference, Brisbane 2009

Unlike many tropical systems elsewhere in the world and their temperate Australian counterparts, rivers in Northern Australia have largely unmodified flow regimes and are comparatively free from the impacts associated with intensive land use. The markedly seasonal hydrology and relatively intact connectivity between river, floodplain and estuary are thought to be important drivers of many of the region's environmental, economic and cultural assets, including productive coastal fisheries, wetlands of international significance and high aquatic biodiversity. Given the increasing interest in the north's water resources, it is essential to determine the environmental water requirements for rivers and wetlands to ensure that these important natural assets are not degraded. This paper outlines the methodology that is being used in the Tropical Rivers and Coastal Knowledge (TRaCK) program to develop generic environmental flow guidelines for northern Australian rivers. The approach follows the recently developed ELOHA (Ecological Limits to Hydrological Alteration) framework for environmental flows. This includes the synthesis of existing hydrologic and ecological databases to develop scientifically defensible and testable relationships between flow alteration and ecological responses. The development of regional environmental flow guidelines is intended to form an integral part of the water planning process.